The Danish Meteorological Institute warned Wednesday that volcanic ash cloud from Iceland will cover Danish airspace again Thursday.

"Ash cloud is moving to Denmark again, due to a change in wind direction in Iceland," said Klaus Larsen, an expert with the institute. Therefore, he said, Danish airspace may be shut down again on Thursday, either totally or partially.

"The ash cloud will float to Denmark during Thursday and Friday. On Saturday it will stay above Denmark," he said.

He predicted that ash cloud will cover part of Jylland, Bornholm and Kastrup airport in Copenhagen at 2:00 p.m. local time (1300 GMT) Thursday, but the concentration of ash will be lower again on Sunday.

Naviair, a company under the Danish Ministry of Transport providing air traffic service, decided Wednesday to open airspace for all flights until 10 a.m. (0900 GMT) Thursday, but will keep Copenhagen Airport open till 2:00 p.m. (1300 GMT).